\documentclass[10pt]{article}

\usepackage{tabularray}
\UseTblrLibrary{booktabs}

\begin{document}

\title{Hello}
\author{Hello}

\maketitle

\section{Table}

Hello world!
Hello world!

\begin{table}[t]
	\begin{tblr}{colspec={Q[c]Q[c]Q[c]Q[c]}}
		\toprule
		aaaaaa & bbbbb & ccc & dd %
		\\
		\cmidrule[r]{1-1} \cmidrule{2-4}
		11 & 2  & 33 & 4          %
		\\
		5  & 66 & 7  & 8          %
		\\
		\bottomrule
	\end{tblr}
\end{table}

\end{document}
